The semiconductor integrated circuit (IC) industry has experienced rapid growth in recent years. Technological advances in IC materials and design have produced generations of ICs where each generation has smaller and more complex circuits than the previous generation. However, these advances have increased the complexity of processing and manufacturing ICs and, for these advances to be realized, similar developments in IC processing and manufacturing are needed. In the course of IC evolution, functional density (i.e., the number of interconnected devices per chip area) has generally increased while geometry size (i.e., the smallest component that can be created using a fabrication process) has decreased.
Semiconductor resistors may be formed on ICs. It is desirable for such resistors to have a low temperature coefficient of resistance (TCR) while also having a high resistance. Traditionally, methods for reducing TCR while maintaining high resistance involved extra film deposition (either polysilicon or SiCR), extra masks, and/or higher costs. In addition, these processes were complicated and sometimes resulted in residue or damage to the device.
Therefore, while existing methods of fabricating semiconductor resistors have been generally adequate for their intended purposes, they have not been entirely satisfactory in every aspect.